Jake Pullen
76 lines
2.2 KiB
Python
76 lines
2.2 KiB
Python
import logging
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# Configure logging
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logging.basicConfig(filename='debug.log', level=logging.DEBUG, format='%(asctime)s - %(levelname)s - %(message)s')
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testing = 1
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if not testing:
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with open(r"2024/07/input.txt", "r") as file:
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input = file.read()
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else:
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input = '''190: 10 19
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3267: 81 40 27
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83: 17 5
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156: 15 6
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7290: 6 8 6 15
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161011: 16 10 13
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192: 17 8 14
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21037: 9 7 18 13
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292: 11 6 16 20'''
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# first we organise the input to something more usable
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input = input.split('\n')
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#print(input)
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input = [x.split(': ') for x in input if x.strip()]
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#print(input)
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input = [(int(x[0]), list(map(int, x[1].split()))) for x in input]
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#print(input)
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# # Find and print the largest target number
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# largest_target = max(input.keys())
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# print(f'The largest target number is: {largest_target}')
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OPERATORS = ['+', '*']
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def generate_expressions(numbers, current_expr=""):
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if len(numbers) == 1:
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yield current_expr + str(numbers[0])
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else:
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for operator in OPERATORS:
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new_expr = current_expr + str(numbers[0]) + operator
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yield from generate_expressions(numbers[1:], new_expr)
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def evaluate_left_to_right(expr):
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tokens = expr.split()
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total = int(tokens[0])
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i = 1
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while i < len(tokens):
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operator = tokens[i]
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next_number = int(tokens[i + 1])
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if operator == '+':
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total += next_number
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elif operator == '*':
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total *= next_number
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i += 2
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return total
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correct_results = []
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for target, numbers in input:
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logging.info(f'Processing target: {target} with numbers: {numbers}')
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for expr in generate_expressions(numbers):
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expr_with_spaces = expr.replace('+', ' + ').replace('*', ' * ')
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result = evaluate_left_to_right(expr_with_spaces)
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if int(result) == int(target):
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correct_results.append(target)
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logging.info(f'Tried {expr} = {result} matches {target}')
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# we can break here because we only need to find one correct expression
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break
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else:
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pass
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logging.info(f'Tried {expr} = {result}, but target is {target}')
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print(f'Sum of correct results: {sum(correct_results)}')
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# too low 2501605300634
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# print(2501605300634 - 2501605301465) |